Impact Of Different Emission Inventories On PM_2.5 Over Beijing-Tianjing-Hebei Area Based On Numerical Study

As the fundamental data for air quality model, emission inventory has great influence on simulation results. To evaluate the impact of different emission inventory on simulating PM2.5,we simulated air quality in the same area and period to isolate the bias due to using different emission inventories.At first, we compared the spatial and temporal characteristics of three different emission inventories(INTEX-B, MEIC10 and MEIC12 emission inventory). Then WRF-Chem was used to simulate PM2.5 over Beijing-Tianjin-Hebei area in April, July, October and December 2014 based on different emission inventories. The comparison of simulated results with observational data showed that the model was able to accurately capture the characteristics of meteorological field such as temperature and wind speed. The model can also basically capture the temporal characteristics of PM2.5. There was tiny influence of simulating PM2.5 based on different emission inventories on meteorological field.Characteristics of simulated PM2.5 over Beijing-Tianjin-Hebei area based on three different emission inventories indicated the simulated PM2.5 values were grossly overestimated based on INTEX-B emission inventory, were more close to observed values by using MEIC12 emission inventory. In addition, though the Taylor graph, the simulation of PM2.5 using three emission inventories was closer to observed values in summer than in other seasons, while in spring,autumn and winter, the simulated PM2.5 was closer to observed values by using MEIC12 emission inventory. In summary, using MEIC12 emission inventory had better performance in simulating PM2.5 over Beijing-Tianjin-Hebei area.In addition, spatial characteristics of simulated PM2.5 based on INTEX-B emission inventory suggested the high PM2.5 value area was stripped which fitted the spatial characteristics of INTEX-B emission inventory; while simulated high PM2.5 value area based on MEIC10 and MEIC12 emission inventory was starlike. Simulation of the chemical components of PM2.5 showed higher concentration of other inorganic aerosol and lower second inorganic aerosol like sulfate,nitrate and ammonium aerosol.